The main Syrian Kurdish armed group defending the Syrian border town on Kobani against Islamic State attackers said on Monday arms air-dropped by the United States would not be enough for it to win the battle, and asked for more support.

Redur Xelil, a spokesman for the Kurdish YPG group, said the weapons dropped overnight would have a "positive impact" on the battle and the morale of fighters who have been out-gunned by Islamic State. But he added: "Certainly it will not be enough to decide the battle."

"We do not think the battle of Kobani will end that quickly. The forces of (Islamic State) are still heavily present and determined to occupy Kobani. In addition, there is resolve (from the YPG) to repel this attack," he told Reuters in an interview conducted via Skype.

Xelil declined to give details on the type of weaponry dropped by U.S. military. The U.S. military said the supplies, described by U.S. officials as "small arms", had been provided by the Kurdish authorities in Iraq.